The
canonical correlation analysis (CCA) forecast of SST in the central Pacific
(Barnett et al. 1988, Science, 241, 192‑196; Barnston and
Ropelewski 1992, J. Climate, 5, 1316‑1345), is shown in Figs.
F1 and F2. This forecast
is produced routinely by the Prediction Branch of the
Climate
Prediction
Center
. The predictions from the National Centers for
Environmental Prediction (NCEP) Coupled Forecast System Model (CFS03) are
presented in Figs. F3 and F4a,
F4b. Predictions
from the Markov model (Xue, et al. 2000: J. Climate, 13,
849‑871) are shown in Figs. F5 and F6.
Predictions from the latest version of the LDEO model (Chen et al.
2000: Geophys. Res. Let., 27, 2585‑2587) are shown in Figs.
F7 and F8.
Predictions using linear inverse modeling (Penland and Magorian 1993:
J. Climate, 6, 1067‑1076) are shown in Figs. F9
and F10. Predictions from the Scripps / Max
Planck Institute (MPI) hybrid coupled model (Barnett et al. 1993: J.
Climate, 6, 1545‑1566) are shown in Fig. F11.
Predictions from the ENSO‑CLIPER statistical model (Knaff and
Landsea 1997, Wea. Forecasting, 12, 633‑652) are shown in
Fig. F12.
Niño 3.4 predictions are summarized in Fig. F13,
provided by the Forecasting and Prediction Research Group of the IRI.
The CPC and
the contributors to the Forecast Forum caution potential users of this
predictive information that they can expect only modest skill.
Outlook
El Niño
conditions are likely to continue into early 2007.
Discussion
Equatorial Pacific SST anomalies greater
than +0.5ºC were observed in most of
the equatorial Pacific during October, with anomalies exceeding +1.0ºC
between 170ºE and 145ºW and between 130ºW and the South
American coast (Fig.
T18).
The latest SST departures in the Niño regions are all near +1.0
(Table T2, Fig. T5).
The value of the Oceanic Niño
Index (ONI; 3-month running mean average of SST anomalies in the Niño 3.4 region –
computed using the Extended Reconstructed SST version-2 data set)
for August-October 2006 is +0.7°C,
which indicates El Niño conditions.
Beginning in February the basin-wide upper ocean heat
content increased, and since early April positive anomalies have been
observed. Since early July
weaker-than-average low-level equatorial easterly winds have been observed
across much of the equatorial Pacific (Fig.
T13). In
October the Southern
Oscillation Index (SOI) was
negative for the sixth consecutive month (Table T1,
Fig. T1). Collectively, these oceanic and atmospheric
anomalies are consistent with the early stages of El Niño in the tropical
Pacific.
Over the past several months
most of the statistical and coupled model forecasts have trended towards
warmer conditions in the tropical Pacific through the Northern Hemisphere
winter (Figs. F1,
F2, F3, F4a,
F4b, F5, F6,
F7, F8, F9,
F10, F11, F12
and F13).
The latest NCEP coupled forecast system (CFS) predictions indicate El
Niño
conditions for the remainder of 2006 and into the NH spring (SH fall) 2007 (Figs.
F3-F4).
More than two-thirds of the other statistical and coupled model
predictions also indicate El Niño conditions during the same period (Fig.
F13).
Typical El Niño effects are likely to
develop over
North America
during
the upcoming winter season, including warmer-than-average temperatures over
western and central
Canada
, and
over the western and northern
United
States
,
wetter-than-average conditions over portions of the U.S. Gulf Coast and
Florida
, and
drier-than-average conditions in the
Ohio
Valley
and the
Pacific
Northwest
. Global effects that can be expected during
November-March include drier-than-average conditions over most of
Malaysia
,
Indonesia
,
some of the U.S.-affiliated islands in the tropical North Pacific, northern
South America
and southeastern
Africa
, and wetter-than-average conditions over equatorial
East Africa
, central
South America
(
Uruguay
, northeastern
Argentina
, and southern
Brazil
) and along the coasts of
Ecuador
and northern
Peru
.
Weekly
updates of SST, 850-hPa wind, OLR and features of the equatorial subsurface
thermal structure are available on the
Climate
Prediction
Center homepage at:
http://www.cpc.ncep.noaa.gov/
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